Method and apparatus for coating an elongated article in coil form



Oct. 11, 1966 A L. P. DE VAU ETAL 3,273,330

METHOD AND APPARATUS FOR COATING AN ELONGATED ARTICLE IN COIL FORM Filed April 29, 1963 5 Sheets-Sheet 1 12., I. Ilii gi 1 J 1: I Li .1." l

INVENTORS Oct. 11, 1966 I... P. DE v u ETAL 3,278,330 METHOD AND APPARATUS FOR COATING AN ELONGATED ARTICLE IN COIL FORM Filed April 29, 1963 5 Sheets-Sheet 2 INVENTORS 100/ 5 P. 05 VAN Oct. 11, 1966 P. DE VAU ETAL 3,278,330

METHOD AND APPARATUS FOR COATING AN ELONGATED ARTICLE IN COIL FORM Filed April 29, 1963 5 Sheets-Sheet 5 74 LF\\ j w-' fir INVENTORS 400/5 P. 96 MN RALPH F/NK BY JACK 7 K/UCH/ JT|J\ T Oct. 11, 1966 P. DE VAU ETAL 3,273,330

METHOD AND APPARATUS FOR COATING AN ELONGATED ARTICLE IN COIL FORM INVENTORS 100/3 P 05 l/A/V P41 P// E F/A/K Oct. 11, 1966 P. DE VAU ETAL 3,273,330

METHOD AND APPARATUS FOR COATING AN ELONGATED ARTICLE IN COIL FORM Filed April 29, 1963 5 Sheets-Sheet 5 T fi' 51?. E.

m 200 z 54 A I I "Z07 AT fPA/E) United States Patent 3,27%,330 METHQD AND APPARATUS FUR COATHNG AN ELONGATED ARTICLE liN CUEL FORM Louis P. De Van, Cleveland, Ralph F. Fink, Kent, and Each '1. Kiuchi, Lakewood, ()hio, assignors to Republic Steel Corporation, (Ileveland, Ohio, a corporation of New Jersey Filed Apr. 29, 1963, Ser. No. 276,355 Claims. (Cl. 11794) This invention relates to a method for applying a plastic coating to tubing, rod, wire, or the like, in coiled form and to apparatus for continuously feeding tubing, rod, wire, or the like, While a plastic coating is being externally applied to a continuously moving length thereof. The invention is particularly described in connection with a method and apparatus for applying coating to a continuous length of tubing in coiled form.

During recent years there has been a substantial demand for plastic coated metal tubing. This demand has not been met in an economical manner 'because the tube coating devices and methods heretofore known have been limited to the coating of individual, straight tubes of limited length. The obvious disadvantage inherent in the coating of straight lengths of tubing arises from the practical difliculty that only relatively short lengths of tubing can be so coated.

Tubing and the like is most easily and economically handled in coils, frequently containing in excess of 1000 feet of tubing. It is conceived that a great saving in time and labor cost can be effected by resort to a continuous coating operation in which the coating is applied while the tubing is maintained in the form of a coil.

It might be suggested that tubing in coiled form be first straightened, the plastic coating applied to the straightened length of tubing and the coated tubing be then recoiled. A procedure involving the uncoiling and recoiling of tubing also has obvious disadvantages. Foremost is the time, space and equipment required. Furthermore, certain tubing when so manipulated may be work hardened to an undesirable extent. Finally, the coating of tubing in coiled form involves the least danger of damage of any kind to the coating or coating applied thereto.

It is, therefore, a specific purpose of the invention to provide a tube coating method which involves rotatably supporting a coil of tubing, separating a turn of the tubing from a coil thereof only in a direction axial of the coil, passing the axially separated tubing into and through a plastic applying zone while continuously rotating the coil on its axis, applying a coating to the tubing as it emerges from the plastic applying zone, guiding the plastic coated tubing into an arcuate path to maintain its coiled form as it emerges from the plastic applying zone, and rotating the coiled coated tubing continuously on the axis of the coil throughout the operation.

It is a specific object of the invention to provide a coil feeding apparatus adapted to support, feed and control a coil of tubing wherein the coil is bodily rotated while one or more turns of the coil are separated and processed while in motion without changing the circular form of the coil.

It is a particular object of the invention to provide a coil feeding apparatus adapted to support, feed and control a coil of tubing while the latter is being coated with a plastic coating composition as it passes through a coating die.

It is a further object of the invention to provide tube coating apparatus adapted to support, guide and feed tubing from a coil thereof while performing a processing operation on a length of the moving tubing, and withal control the movement of the tubing in a manner to ice maintan the same in coiled form While the processing operation is being performed.

To the end that the objects and purposes of the invention may be carried out, the coil feeding apparatus herein provides a coil support permitting large coils of tubing to turn bodily about the coil axis with great freedom while one or more turns of the coil are separated into an adjacent plane for processing in combination with means for guiding and receiving coated tubing in coiled form.

In its more specific aspect the coil apparatus herein provides anti-friction coil supporting means disposed both radially and axially of the coil, whereby the coil is restrained to the apparatus but is entirely free to turn with ease about its axis.

Further objects and advantages of the invention together with the arrangements of parts and their functions, will become clear as the specification is read in light of the drawings, in which drawings like reference numerals indicate like parts, and in which:

FIG. 1 is a side elevational view of the coil feeding apparatus with which this invention is concerned;

FIG. 2 is a plan view partially in section, taken on line 22 of FIG. 1;

FIG. 3 is a vertical sectional view taken on line 33 of FIG. 2;

FIG. 4 is a sectional detail of one of several radial coilsupporting stub rollers in the stand;

FIG. 5 is a detail sectional view representative of several flanged tube guide rollers embodied in the machine;

FIG. 6 is a plan view of tube feeding mechanism embodied in the stand;

FIG. 7 is a vertical View, partially in section, taken on line 77 of FIG. 6;

FIG. 8 is a vertical sectional view of an undercoating applicator embodied in the apparatus;

FIG. 9 is a vertical sectional view of an extrusion die assembly embodied in the stand; and

FIG. 10 is a vertical sectional view through a coilreceiving drum.

In its essence, the coil feeding apparatus herein provides an anti-friction coil cradle 10 which is so constructed and arranged as to support coiled tubing, rod, or wire on antifriction members such that the coil is free to turn. The coil cradle 10 is composed of a coil-supporting bed 12 and a semi-circular cage =14. The coil-supporting bed 12 is shown in FIG. 1 as being disposed horizontally to receive a coil 16 of tubing, rod, or wire thereon while the semicircular cage 14 extends upwardly from the coilsupporting bed 12 to provide support for the outer face of the coil 16.

The coil-supporting bed 12, as best shown in FIG. 2, consists of a flanged annulus 18 on which are mounted a plurality of radial anti-friction stub rollers 20, 22, 24, 26, 28 30, 32 and 34. The radial stub rollers are of sufficient length to afford support to the coil 16.

The semi-circular cage 14 is composed of a flanged, semi-circular crown 36 held in spaced relation to the coilsupporting bed 12 by means of a plurality of supports 38. Mounted between the semi-circular crown 36 of the cage structure and the coil-supporting bed 12 are a plurality of elongated anti-friction rollers 40, 42, 44, 46 and 48. These rollers, together with a pair of short restraining rollers 50 and 52, effectively restrain the coil 16 in the coil cradle and provide anti-friction supports for the coil in the lateral direction,

At the back of the coil feeding apparatus and below the coil-supporting bed 12 is an undercoating applicator 52 and an extrusion die assembly 54. A first tube feeder 56 feeds the tube into the undercoating applicator 52 and into the extrusion die 54. As the coated tubing emerges from the extrusion die assembly 54, the coating is cooled by a suitable coolant delivered to the coated tubing by a plurality of coolant nozzles 58. The end of the coated tubing is then engaged by a second tube feeder 60 which delivers the coated tubing to a coil-receiving drum 62.

In initiating the coating operation, the leading end of the tubing is separated from the coil in the direction of the coil axis as it passes the radial roller 28. The separated end of the tubing is directed under the radial stub roller 30 and is then brought under a flanged guide roller 64 at the front of the stand. The flanged guide roller 64 is supported from the flange of the coil-supporting bed 12 and is dependent therefrom such that it is disposed in a plane which is horizontally spaced from that in which the radial stub rollers operate. As the end of the tubing is further advanced, the leading end of the tubing is brought under a second flanged guide roller 66 which is also dependent from the flange of the coil-supporting bed 12. This latter guide roller positions the end of the tubing to enter the first tube feeder 56 which feeds the tubing through the coating devices, as previously explained. The length of the tubing which has been separated from the coil and which is in the process of being coated is supported in its course by a plurality of short depending axial rollers, such as rollers 68 and 70, which are shown in FIG. 1. A second set of such rollers (not shown) are located in corresponding positions at the opposite side of the coil-supporting bed 12.

From the foregoing, it can be seen that a continuous coating process can be performed on coiled tubing or rod without the necessity of uncoiling the same and that the coated tubing is delivered to the coil-receiving drum 62 in coiled form. As stated above, straight lengths of tubing and rod have heretofore been coated in extrusion dies quite similar to that employed herein, but such coating operations were not performed on tubing or rod in the form of a coil. The time and labor saving advantage accruing from the use of a coil feeding apparatus, such as generally described, can be readily appreciated.

FIGS. 3 through disclose the details of the various anti-friction supporting and guiding rollers which are employed in the structure. In FIG. 3, the elongated antifriction roller 40 and the short depending roller 70 are both mounted on a roller support 72 which is fixed in the flange 74 of the semi-circular crown 36 and in the flange 18 of the coil-supporting bed 12, Both rollers 40 and 70 are mounted on the roller support 72 by sets of roller bearings 78 and 80 at opposite ends of the rollers.

The radial stub rollers, of which the roller 20 of FIG. 4 is typical, are mounted in a mounting hub 82 by means of a pin 84. The mounting hub 82 is welded to the flange 18 of the coil-supporting bed 12. The pin 84 is held therein against turning movement in the mounting hub, and the roller 20 is mounted on the pin by means of a set of anti-friction bearings 88 and 90; these bearings being located at opposite ends of the rollers.

FIG. 5 is typical of the depending flanged guide rollers 64, 66 and 67. The only difference in the structure of the several depending flanged guide rollers is the horizontal plane in which they are disposed. The position of the guide rollers is determined by the length of a depending bracket 92 attached to the flange of the coil-supporting bed 12. As seen in FIG. 5, the flanged guide roller 66 is mounted on an inwardly extending pin 94 carried at the free end of the depending bracket 92. The guide roller is mounted on the pin 94 by a set of anti-friction bearings 96 and 98.

A typical coil feeding apparatus may be five or six feet in diameter, adapting it to handle coils containing in excess of 1000 feet of tubing or rod.

The tube feeders 56 and 60 are substantially identical such that a description of the first tube feeder 56, as shown in FIGS. 6 and 7, will also serve as a description of the second tube feeder 60. As shown in FIG. 6, the tube feeder includes a first power roller 100 and a second power roller 102. These rollers operate respectively in 4 conjunction with a first idler roller 104 and a second idler roller 106, such that the tube 16 is engaged between these respective sets of rollers and is driven therethrough when the power rollers are rotated. FIG. 7 shows an hydraulic motor 108 associated in driving relation to the first power roller 10. A similar hydraulic motor is likewise associated with the second power roller for driving the latter.

The power rollers and 102 are mounted on an adjustable mounting plate and the idler rollers 104 and 106 are mounted on an adjustable mounting plate 112. The mounting plates 110 and 112 are supported by a bed plate 114 which has a pair of guide ribs 116 and 118 at opposite ends thereof. Adjustment of the mounting plates 110 and 112 accommodates the tube feeders to tubing, or rod, of varying diameter. The mounting plate 110 is held against the bed plate 114 by a pair of machine screws 120 and 122 which extend into the bed plate 114 through slots 1 24 and 126 of the mounting plate. By the same token, the mounting plate 112 is held to the bed plate 114 by means of a pair of machine screws 128 and 130 extending through slots 132 and 134 of the latter mounting plate. Along the outer edge of each mounting plate is an upstanding screw-threaded lug 136 adapted to receive an adjusting screw 138 which can be turned by a hand wheel 140 to rotate the screw 138. The adjusting screw 138 is fixed against axial movement in an upstanding lug 142 in the bed plate 114. A similar adjusting arrangement is provided for the mounting plate 112.

From the foregoing it can be seen that adjustment of the gap between the respective sets of rollers is readily accomplished by relieving the screws 120, 122, .128 and 130 and then turning the hand wheels 140 as may be necessary. The mounting plates 110 and 112 are then held in adjusted position by tightening the screws 120, 122, 128 and 130. The tube feeder assembly is fixed to a suitable support 144 by means of a pair of screws 146 and 148 which operate, respectively, in somewhat arcuate elongate slots 150 and 152 formed in the bed plate 114. The slots 150 and 152 permit limited angular adjustment of the tube feeder on its support 144.

FIG. 7, which is a vertical sectional view on line 7-7 of FIG. 6, shows the manner in which the tube feeding rollers are mounted. Thus the roller 100, which is power driven by the hydraulic motor 108, is mounted by means of a bearing sleeve 154 which is fixed to and extends upwardly from the mounting plate 110. The power roller 100 is recessed to receive a bearing assemby 156 which is effectively retained between the bearing sleeve 154 and the wall of the roller cavity. A drive sleeve 158 is keyed to the shaft 160 of the hydraulic motor 108 and this drive sleeve is, in turn, keyed to a hub 162 of the roller, whereby rotary power is transmitted from the hydraulic motor 108 to the power roller 100.

The idler roller 104 is somewhat similarly mounted on its mounting plate 112 which has fixed thereto an upstanding bearing sleeve 164 for receiving the roller. A bearing retaining ring 166 holds anti-friction bearings 168 against the bearing sleeve 164, and a cavity formed in the idler roller 104 snugly embraces the bearing retainer 166. The rollers 102 and 106 are constructed and mounted as described in respect to rollers 100 and 104, respectively.

While the foregoing is a particular description of the first tube feeder 56, we have stated that the second tube feeder 60 is substantially identical. The only difference between the two feeders is found in the fact that the tube gripping surfaces of the rollers of the second tube feeder 60 are preferably covered with relatively resilient material, such as rubber, to guard against damage to the still relatively soft coating of the tube as it passes through the second tube feeder.

As stated above, the coating process involves the application of a hot undercoating to the exterior of the tubing prior to the application of the plastic coating material.

As the tubing emerges from the first tube feeder 56, it is passed through the undercoating applicator 52 which is shown in cross-section in FIG. 8. The applicator includes a simple enclosure 170 constituting an undercoating trap. The trap has a passage 172 in its inner side Wall through which the tubing passes. Near the top of the trap is an undercoating inlet tube 174 and in the bottom of the trap is an undercoating drain tube 176. An exit passage 178 is formed in the far face of the trap generally in alignment with the entrance passage 172. Any suitable undercoating may be applied to the tube as it passes through the applicator. One undercoating material which has been successfully utilized is made by Farboil Company of Baltimore, Maryland under the identifying designation of RSCl4000-2. As the hot undercoating is fed through the undercoating inlet 174, it flows upon the tubing 16 as it passes through the undercoating trap. An undercoating wiper 180 through which the tube passes as it leave-s the undercoating applicator serves to spread the undercoating evenly and to remove excess adhesive from the tube. The wiper 180 has a central aperture which corresponds substantially to the outer diameter of the tubing. The wiper is preferably formed of relatively soft elastomeric material such as gum rubber.

The wiper 180 is mounted in a floating wiper plate 182 which is held against the undercoating trap by means of a wiper plate clamp 184, the latter being attached to the undercoating trap by means of a plurality of circumferentially spaced screws 186. The floating wiper plate 182 has an annular flange 188 which is seated in a groove 190 formed in the inner face of the wiper plate clamp 184. The diameter of the groove 190 is somewhat larger than the diameter of the flange 188 such that the Wiper plate 182 is free to float with the tubing 16 as the lateral alignment of the tubing may vary upon emerging from the applicator. The floating wiper plate is centered by means of a plurality of spring-pressed lugs 192 seated in the wiper plate clamp 184 and projecting inwardly therefrom into contact with the floating wiper plate 182. A face plate 194 held to the floating wiper plate 184 by means of .a plurality of circumferentially spaced screws 1% holds the wiper 180 within a cavity of the floating wiper plate 182.

As briefly stated above, as the undercoating coated tubing 16 emerges from the undercoating applicator, it is introduced to the extrusion die assembly 54 where the plastic coating, such as a hot linear high density polyethylene, is applied as a film to the exterior of the tube. One plastic composition which has been successfully employed is Marlex-SOOS, manufactured and sold by Phillips Chemical Company.

The extrusion die assembly 54 is more completely shown in the sectional view thereof in FIG. 9. By reference to that figure, it can be seen that the extrusion die includes a housing 198 to which a heated plastic composition is fed by way of a plastic inlet 200. The plastic is fed to the die under pressure by means of and from a source not shown.

The extrusion die itself consists of a die annulus 202 and a concentric die cone 204. The die annulus 202 is held against the annular housing 198 by means of a bezel 206 which is held against the annular die housing by means of a plurality of circumferentially spaced screws 207. A spacing ring 208 may be interposed between the die annulus 202 and a shoulder 210 formed at the mouth of the annular die housing. The spacing ring 208 is centered by means of a plurality of screws 212 circumferentially spaced along the annular die housing and extending therethrough in a radial direction into contact with the ring. The die annulus 202 is also centered by a plurality of screws 214 which extend through the bezel 206 in a radial direction at spaced circumferential point and into contact with a land 216 formed on the die annulus 202.

The cone 204 which forms the inner member of the extrusion die assembly has a flange 218 by which the cone is attached to the housing by means of a plurality of screws 220 extending through the flange and into the rear face of the annular housing 198.

In applying the coating, the tubing 16 is driven through the extrusion die assembly at a rate somewhat in excess of that at which the plastic coating material is forced from the extrusion die. This results in the maintenance 222 between the surface of the tubing and the plastic being extruded from the die. Furthermore, it has the effect of stretching the plastic coating into tight engagement with the tubing being coated.

As the coated tubing leaves the extrusion die assembly, the coating thereon is cooled and solidified by a coolant, such as water, which is directed against the coated tubing from the coolant nozzles 58, as shown in FIG. 2. The now coated tubing next passes through the second tube feeder 60 which, as stated, preferably has a relatively soft cover on the tube gripping faces of its rollers.

An important feature of the invention lies in the fact that the several tubing supports and guides form an arcuate path for the moving tubing, and that the tube engaging and driving rollers 56 and 60 are arranged along said arcuate path such that the course of the path extends between rollers of the respective sets.

As the coated tubing leaves the second tube feeder 60, it passes over the radial stub roller 30 and is then directed into the coil-receiving drum 62. Whether or not the tubing moves over or under the several depending guide rollers will depend somewhat on the stiffness of the tubing. In the case of relatively flexible tubing, the tubing is apt to sag in which event the guide rollers may support the tubing. In the case of a relatively stiff tubing, the springiness thereof may resist sagging in which even-t the tubing may be trained under a particular depending guide roller.

For purpose of explanation, we have illustrated eight radial coil-supporting stub rollers all of which are supported from the flange of the coil-supporting bed and all of which are in the same horizontal plane. It may be found that for some purposes this member may be either increased or decreased. Furthermore, it is contemplated that certain of these coil-supporting rollers may be arranged in different horizontal planes. The diameter of the coil feeding stand, as Well as the flexibility of the tube being coated, will have some bearing on the number and location of the radial coil-supporting rollers.

Experimentation will demonstrate the best position for the rollers for any given operation.

As the coated tubing emerges from the coating die, it is guided into the tube receiving drum 62. The drum is mounted for rotation under the impetus of the moving tube. As shown in FIG. 10, the drum is composed of an upstanding annular side wall 228 and a bottom Wall 230. A plurality of radial reinforcing ribs 232 support the bottom of the drum.

The essential characteristic of the drum is that it be rotatable and to the end that it may rotate easily, it is mounted on a drum stem 234. The stem is mounted in a seat 236 at the axis of a base spider 238, the arms of the spider being provided with casters 240 to facilitate movement of the drum into and out of coil receiving position.

The drum is mounted on the drum stern 234 by means of a pair of bearing sleeves 242 and 244. The elevation of the drum along the drum stem is determined by a pair of shaft collars 246 which are suitably fixed to the drum stem by any convenient means such as set screws.

The bearing sleeves 242 and 244 are seated on and affixed to end plates 248 and 250, respectively. These end plates constitute caps for a center tube 252 which is seated in an annular groove in the confronting faces of the end plate.

It may be found advantageous to apply a positive driving force to the drum for driving it in rotation. This advantage will become more evident with the larger coils. Furthermore, it is suggested that thecoil supportin rollers be also driven. In this event, the drum and the rollers should be driven in synchronism.

While the novel features of the invention have been illustrated and described in connection with a specific embodiment of the invention, it is believed that this embodiment will enable others skilled in the art to apply the principles of the invention in forms departing from the exemplary embodiment herein, and such departures are contemplated by the claims.

We claim:

1. The method of applying a plastic coating to a length of tubing in coiled form comprising the steps: rotatably supporting a coil of tubing, separating a turn of tubing from said coil only in a direction axial of said coil, passing said axially separated tubing into and through a plastic applying zone while continuously rotating said coil on its axis, applying a plastic coating to said tubing as it emerges from said plastic applying zone, guiding said plastic coated tubing into an arcuate path to maintain its coiled form as it emerges from said plastic applying zone, and rotating said coiled coated tubing continuously on the axis of its coil throughout the coating operation.

2. The method of applying a plastic coating to a length of tubing in coiled form comprising the steps: rotatably supporting a coil of tubing in a horizontal plane, separating a turn of tubing from said coil only in a direction axial of said coil, passing said axially separated tubing into and through a plastic applying zone While continuously rotating said coil on its axis, applying a driving force to said tubing as it enters and emerges from said coating zone, applying a plastic coating to said tubing as it emerges from said plastic applying zone, guiding said plastic coated tubing into an arcuate path to maintain its coiled form as it emerges from said plastic applying zone, and rotating said coiled coated tubing continuously on the axis of its coil throughout the coating operation.

3. The method of applying a plastic coating to a length of tubing in coiled form comprising the steps: rotatably supporting a coil of tubing, separating a turn of tubing from said coil only in a direction axial of said coil, passing said axially separated tubing into and through a plastic applying zone while continuously rotating said coil on its axis, applying a hot plastic coating to said tubing as it emerges from said plastic applying zone, guiding said plastic coated tubing into an arcuate path to maintain its coiled form as it emerges from said plastic applying zone, cooling said coated tubing by application of a cooling fluid thereto as it emerges from said coating zone, and rotating said coiled coated tubing continuously on the axis of its coil throughout the coating operation.

4. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, radial and axial anti-friction means for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said supporting means into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said supporting means and a separated turn thereof is moved through said processing station, and means for receiving in coiled form processed lengths of said coil emerging from said processing station.

5. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, a plurality of horizontal and vertical anti-friction rollers for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said supporting rollers into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said supporting rollers and a separated turn thereof is moved through said processing station, and means for receiving in coiled form processed lengths .of said coil emerging from said ,processing station,

6. In a mechanism for processing a moving length of tube, rod, wire, 'or the like from a coil thereof, a plurality of horizontal and vertical anti-friction rollers for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said supporting rollers into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said supporting rollers and a separated turn thereof is moved through said processing station, and rotary means for receiving in coiled form processed lengths of said coil emerging from said processing station.

7. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, radial and axial anti-friction means for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said supporting means into a plane spaced from said coil, plastic coating means in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said supporting means and a separated turn thereof is moved through said plastic coating, and means for receiving in coiled form coated lengths of said coil emerging from said plastic coating means.

8. In a mechanism for processing a moving length of tube, rod, Wire, or the like from a coil thereof, a plurality of radial and anti-friction rollers for supporting a coil for free turning movement about its axis, axial antifriction rollers for restraining the lateral movement of a coil on said radial anti-friction rollers, a plurality of guide rollers axially spaced from said radial anti-friction rollers for guiding a turn of a coil on said radial antifriction rollers into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said radial anti-friction rollers and a separated turn thereof is moved through said processing station, and means for receiving in coiled form processed lengths of said coil emerging from said processing station.

9. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, radial and axial anti-friction means for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said supporting means into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said supporting means and a separated turn thereof is moved through said processing station, and rotary coil-receiving means for receiving in coiled form processed lengths of said coil emerging from said processing station.

10. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, a plurality of radial anti-friction means for supporting a coil for free turning movement about its axis, axial anti-friction means for restraining the lateral movement of a coil on said radial anti-friction means, a plurality of guides axially spaced from said radial anti-friction means for guiding a turn of a coil on said supporting means into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said radial anti-friction means and a separated turn thereof is moved through said processing station, and a rotary support for receiving in coiled form processed lengths of said coil emerging from said processing station.

11. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, a plurality of anti-friction rollers for supporting a coil for free turning movement about its axis, axial anti-friction rollers for restraining the lateral movement of a coil on said radial anti-friction rollers, a plurality of guides axially spaced from said anti-friction rollers for guiding a turn of a coil on said supporting means into a plane spaced from said coil, a plastic coating die in said latter plane,

means for applying a driving force to said coil whereby said coil is rotated on said radial anti-friction rollers and a separated turn thereof is moved through said plastic coating die, and means for receiving in coiled form processed lengths of said coil emerging from said processing station. 7

12. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, an annular table, radial and axial anti-friction means carried by said table for supporting a coil on said table for free turning movement about its axis, means for guiding :a turn of a coil on said table into a plane spaced from said coil, a processing station in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said table and a separated turn thereof is moved through said processing station, and means for receiving in coiled form processing lengths of said coil emerging from said processing station.

13. In a mechanism for processing a moving length of tube, rod, wire, or the like from a coil thereof, an annular table, radial and axial anti-friction means carried by said table for supporting a coil for free turning movement about its axis, means for guiding a turn of a coil on said table into a plane spaced from said coil, a plastic applying die in said latter plane, means for applying a driving force to said coil whereby said coil is rotated on said table and a separated turn thereof is moved through said plastic applying die, and a rotary support for receiving in coiled form coated lengths of said coil emerging from said plastic applying die.

14. In a machine for processing a moving length of tube in a coil thereof, a table adapted to support and guide a coil in rotation, means for guiding a turn of a coil on said table into an ancuate plane spaced laterally of said coil, a plastic applying die having an entrance side and an exit side in said latter plane, a first set of tube engaging and driving rollers at the entrance side of said die, and :a second set of tube engaging and driving rollers at the exit side of said die, the rollers of each set being arranged along said plane such that the arcuate course thereof extends between rollers of said sets.

15. In a machine for processing a moving length of tube in a coil thereof, a table adapted to support and guide a coil in rotation, means for guiding a turn of a coil on said table into an arcuate plane spaced laterally of said coil, 2. plastic applying die having an entrance side and an exit side in said latter plane, a first set of tube engaging and driving rollers at the entrance side of said die, a second set of tube engaging and driving rollers at the exit side of said die, the rollers of each set being arranged along said plane such that the arcuate course thereof extends between rollers of said sets, and means for adjustably mounting said sets of tube engaging and driving rollers along said plane.

References Cited by the Examiner UNITED STATES PATENTS 2,061,388 11/1936 Schou 1l7-232 2,324,645 7/ 1943 Prehler 18-14 2,513,106 6/1950 Prendergast. 2,739,616 3/1956 Duff. 2,779,976 2/1957 Roberts et a1. 2,797,730 7/ 1957 Martin. 2,904,846 9/1959 Smith 1813 2,931,096 4/ 1960 McCormick. 2,963,749 12/1960 Pavlic. 3,225,385 12/ 1965 Kleine 1813 ALFRED L. LEAVITT, Primary Examiner.

E. B. LIPSCOMB, Assistant Examiner. 

1. THE METHOD OF APPLYING A PLASTIC COATING TO A LENGTH TUBING IN COILED FORM COMPRISING THE STEPS: ROTATABLY SUPPORTING A COIL OF TUBING, SEPARATING A TURN OF TUBING FROM SAID COIL ONLY IN A DIRECTION AXIAL OF SAID COIL, PASSING SAID AXIALLY SEPARATED TUBING INTO AND THROUGH A PLASTIC APPLYING ZONE WHILE CONTINUOUSLY ROTATING SAID COIL ON ITS AXIS, APPLYING A PLASTIC COATING TO SAID TUBING AS IT EMERGES FROM SAID PLASTIC APPLYING ZONE, GUIDING SAID PLASTIC COATED TUBING INTO AN ARCUATE PATH TO MAINTAIN ITS COILED FORM AS IT EMERGES FROM SAID PLASTIC APPLYING ZONE, AND ROTATING SAID COILED COATED TUBING CONTINUOUSLY ON THE AXIS OF ITS COIL THROUGHOUT THE COATING OPERATION. 